I did a few searches and didnt find much so ill try this out. Since winter started my car would always seem to run on the cold side, the temp gauge would only get to the mid way point if the car was at idle or i was in traffic. Other wise it would sit at around 1/4 past the C line. I recently swapped my motor last weekend and now it will only get to 1/4 past the "c" mark if im idling or in traffic. When driving on the hwy or in town it will be bellow the "c"line/mark like it is when you first start your car. When it actually gets up to 1/4 on the gauge it will blow out hot air, but of course when it drops it blows out cold air. My 1st guess was the thermostat but i wanted to see if anyone else has ever had this similar issue. Ive got my old/spare motor so i do have all of the sensors still on the block that i can use if i need to. Thanks in advance.

 

did you bleed your coolant system? if your temp gauge is surging back and forth then you have air bubbles in your system

 

yes i did, and no its not surging back and forth.

 

tried the ghetto cardboard trick in front of the radiator and that worked. might try swapping a few things out tomorrow since i havent gotten much of a response.

 

theres only a few things it could be. you don't need cardboard.

1. air in coolant or low coolant level
2. plugged heatercore
3. thermostat stuck open/opens too soon

sounds like a thermostat to me.

 

yeah i know i dont need cardboard, i was using that as a temperary fix until i could get the time to really look at it. im gona flush the coolant and do a new thermostat asap.

 

had the same problem on my old winter beater, drove half the winter with cardboard, then changed the thermostat and boom , it was nice and warm again.

The thermostat failed open ( as it should ), so the car really never had a change to warm up the coolant.

 

hopefully thats all it is. ill see tomorrow afternoon.

 

it was the thermostat, or actually the lack of thermostat. there wasnt one in there at all so that explains it.